U.S. patent application number 14/546249 was filed with the patent office on 2015-05-28 for imaging apparatus having bending optical element.
This patent application is currently assigned to HOYA CORPORATION. The applicant listed for this patent is HOYA CORPORATION. Invention is credited to Isao OKUDA.
Application Number | 20150146087 14/546249 |
Document ID | / |
Family ID | 53136889 |
Filed Date | 2015-05-28 |
United States Patent
Application |
20150146087 |
Kind Code |
A1 |
OKUDA; Isao |
May 28, 2015 |
IMAGING APPARATUS HAVING BENDING OPTICAL ELEMENT
Abstract
An imaging apparatus includes an imaging optical system, a
bending optical element and an image sensor; an inclination
adjusting plate which mounts the image sensor onto a housing with a
pair of opposed sides of the image sensor extending in a direction
orthogonal to a pre-bending optical axis, of the imaging optical
system; a pair of end portions formed on the inclination adjusting
plate and positioned outside the pair of opposed sides of the image
sensor; a swing fulcrum formed between an inner end portion, which
is closest to the pre-bending optical axis, and the housing; and an
inclination adjuster provided between an outer end portion, which
is farthest from the pre-bending optical axis out, and the housing,
to make the inclination adjustment plate swing about the swing
fulcrum to adjust the inclination adjustment plate.
Inventors: |
OKUDA; Isao; (Saitama,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HOYA CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
HOYA CORPORATION
Tokyo
JP
|
Family ID: |
53136889 |
Appl. No.: |
14/546249 |
Filed: |
November 18, 2014 |
Current U.S.
Class: |
348/360 |
Current CPC
Class: |
H04N 5/2254 20130101;
H04N 5/2252 20130101; G02B 13/009 20130101 |
Class at
Publication: |
348/360 |
International
Class: |
H04N 5/225 20060101
H04N005/225; G02B 13/00 20060101 G02B013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2013 |
JP |
2013-246374 |
Claims
1. An imaging apparatus comprising: an imaging optical system
including at least one lens group, at least one bending optical
element which bends a light bundle emanating from an object, and an
image sensor having a rectangular shape, in a plan view thereof,
which lies on a post-bending optical axis of said imaging optical
system, said post-bending optical axis being optically bent by said
bending optical element; a housing which supports said imaging
optical system; an inclination adjusting plate which mounts said
image sensor onto said housing with a pair of sides of said image
sensor that are opposed to each other extending in a direction
orthogonal to a pre-bending optical axis, of said imaging optical
system, before being optically bent by said bending optical
element; a pair of end portions formed on said inclination
adjusting plate and positioned outside said pair of opposed sides
of said image sensor, respectively; a swing fulcrum formed between
an inner end portion, which is closest to said pre-bending optical
axis out of said pair of end portions, and said housing; and an
inclination adjuster which is provided between an outer end
portion, which is farthest from said pre-bending optical axis out
of said pair of end portion, and said housing, to make said
inclination adjustment plate swing about said swing fulcrum to
adjust an inclination of said inclination adjustment plate.
2. The imaging apparatus according to claim 1, wherein said
inclination adjuster comprises: a biaser provided between said
housing and said outer end portion of said inclination adjusting
plate to bias said outer end portion in a direction away from said
housing; and a pair of adjustment screws provided spaced from each
other, in a direction orthogonal to a plane on which said
pre-bending optical axis and said post-bending optical axis lie, to
engage said outer end portion with said housing, and wherein said
pair of adjustment screws pass through holes formed in said housing
to extend toward said inclination adjusting plate side, and wherein
ends of threaded portions of said pair of adjustment screws are
screw-engaged with said outer end portion.
3. The imaging apparatus according to claim 2, wherein said
inclination adjusting plate comprises a mounting plate portion,
onto which said image sensor is mounted, wherein said outer end
portion of said inclination adjusting plate comprises a proximate
plate portion which is closer to said housing than said mounting
plate portion, and wherein said pair of adjustment screws are
screw-engaged with said proximate plate portion.
4. The imaging apparatus according to claim 3, wherein said ends of
said threaded portions of said pair of adjustment screws are
positioned closer to said housing than said mounting plate portion
of said inclination adjusting plate.
5. The imaging apparatus according to claim 1, wherein said swing
fulcrum comprises: a fulcrum projection which is formed on said
inclination adjusting plate substantially at a center of said inner
end portion with respect to a lengthwise direction thereof, said
fulcrum projection projecting in a direction away from said bending
optical element; and a contact portion formed on said housing to
contact said fulcrum projection.
6. The imaging apparatus according to claim 2, wherein said biaser
comprises a pair of compression coil springs which are arranged to
correspond to said pair of adjustment screws.
7. The imaging apparatus according to claim 1, wherein said bending
optical element is provided between said image sensor and a lens
group, of said imaging optical system, that is provided closest to
the image side.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an imaging apparatus having
at least one bending optical element, and in particular relates to
such an imaging apparatus which is small in size and equipped with
an inclination adjusting mechanism for adjusting the inclination of
an image sensor.
[0003] 2. Description of the Related Art
[0004] In recent years, mobile electronic devices which are
designed mainly for taking still/moving photographic images, such
as digital cameras (still-video cameras) and digital camcorders
(motion-video cameras), and other mobile electronic devices which
are designed to be capable of taking such photographic images as a
subsidiary function, such as mobile phones equipped with a camera
and tablet computers, etc., equipped with a camera, have become
widespread, and there has been a demand to miniaturize the imaging
units incorporated in these types of mobile electronic devices. In
order to miniaturize an imaging unit, it is known to configure an
optical system of an imaging unit as a bending optical system which
reflects (bends) a light bundle using a reflection surface of a
reflecting element (bending optical element) such as a prism or a
mirror. An imaging optical system having at least one bending
optical element (hereinafter also referred to as the "imaging
apparatus") is advantageous in achieving a reduction in thickness
of the imaging unit, especially in the travelling direction of the
incident light emanating from an object to be photographed.
[0005] In such an imaging apparatus, an image sensor (image pickup
device) is arranged on a post-bending optical axis (the optical
axis after being optically bent by a bending optical element).
Usually the image sensor is fixed to an image sensor board
(image-sensor mounting board) that is provided as a separate member
from the image sensor, and this image sensor board is fixed to a
housing which supports an imaging optical system (which includes
lens groups and at least one prism). An adjusting mechanism for
adjusting the inclination of such an image sensor relative to a
plane orthogonal to an optical axis is known in the art and
disclosed in, e.g., Japanese Unexamined Patent Publication No.
2006-293187. However, this adjusting mechanism is unsuitable for
achieving a reduction in thickness (slimming down) of the imaging
unit.
[0006] Further examples of the related art are also disclosed in
Japanese Unexamined Patent Publication Nos. 2006-267391,
2010-243763, and 2013-105049.
SUMMARY OF THE INVENTION
[0007] The present invention provides an imaging apparatus, wherein
the inclination of an image sensor which lies on a post-bending
optical axis (the optical axis after being optically bent by a
bending optical element that is positioned adjacent to the image
sensor) relative to a plane orthogonal to the post-bending optical
axis is adjustable. In addition, the present invention provides an
imaging apparatus, in which the thickness and the width of an
imaging optical system thereof, in particular, can be kept small
even though the imaging apparatus is equipped with an image sensor
inclination adjusting mechanism, wherein a left-right length is
defined as the dimensions of an imaging optical system in an
optical axis direction thereof (in a direction of a pre-bending
optical axis), the thickness is defined as the dimensions of the
imaging optical system in a direction of a post-bending optical
axis, and the width is defined by the dimensions of the imaging
optical system in a direction orthogonal to both the left-right
length and the thickness direction.
[0008] According to an aspect of the present invention, an imaging
apparatus is provided, including an imaging optical system
including at least one lens group, at least one bending optical
element which bends a light bundle emanating from an object, and an
image sensor having a rectangular shape, in a plan view thereof,
which lies on a post-bending optical axis of the imaging optical
system, the post-bending optical axis being optically bent by the
bending optical element; a housing which supports the imaging
optical system; an inclination adjusting plate which mounts the
image sensor onto the housing with a pair of sides of the image
sensor that are opposed to each other extending in a direction
orthogonal to a pre-bending optical axis, of the imaging optical
system, before being optically bent by the bending optical element;
a pair of end portions formed on the inclination adjusting plate
and positioned outside the pair of opposed sides of the image
sensor, respectively; a swing fulcrum formed between an inner end
portion, which is closest to the pre-bending optical axis out of
the pair of end portions, and the housing; and an inclination
adjuster which is provided between an outer end portion, which is
farthest from the pre-bending optical axis out of the pair of end
portion, and the housing, to make the inclination adjustment plate
swing about the swing fulcrum to adjust an inclination of the
inclination adjustment plate.
[0009] It is desirable for the inclination adjuster to include a
biaser provided between the housing and the outer end portion of
the inclination adjusting plate to bias the outer end portion in a
direction away from the housing; and a pair of adjustment screws
provided spaced from each other in a lengthwise direction of the
outer side end portion to engage the outer end portion with the
housing. The pair of adjustment screws pass through holes formed in
the housing to extend toward the inclination adjusting plate side.
Ends of threaded portions of the pair of adjustment screws are
screw-engaged with the outer end portion.
[0010] It is desirable for the inclination adjusting plate to
include a mounting plate portion, onto which the image sensor is
mounted, wherein the outer end portion of the inclination adjusting
plate includes a proximate plate portion which is closer to the
housing than the mounting plate portion, and the pair of adjustment
screws are screw-engaged with the proximate plate portion.
[0011] It is desirable for the ends of the threaded portions of the
pair of adjustment screws are positioned closer to the housing than
the mounting plate portion of the inclination adjusting plate.
[0012] It is desirable for the swing fulcrum to include a fulcrum
projection which is formed on the inclination adjusting plate
substantially at a center of the inner end portion with respect to
a lengthwise direction thereof, the fulcrum projection projecting
in a direction away from the bending optical element; and a contact
portion formed on the housing to contact the fulcrum
projection.
[0013] It is desirable for the biaser to include a pair of
compression coil springs which are arranged to correspond to the
pair of adjustment screws.
[0014] It is desirable for the bending optical element to be
provided between the image sensor and a lens group, of the imaging
optical system, that is provided closest to the image side.
[0015] According to the present invention, an imaging apparatus can
be obtained which is equipped with an inclination adjusting
mechanism for adjusting the inclination of an image sensor and is
small, especially in thickness and width directions.
[0016] The present disclosure relates to subject matter contained
in Japanese Patent Application No. 2013-246374 (filed on Nov. 28,
2013) which is expressly incorporated herein by reference in its
entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be described below in detail with
reference to the accompanying drawings in which:
[0018] FIG. 1 is an external perspective view of an embodiment of
an imaging apparatus according to the present invention;
[0019] FIG. 2 is a perspective view of the imaging apparatus,
showing an internal structure thereof;
[0020] FIG. 3 is a sectional view taken along the line III-III
shown in FIG. 1;
[0021] FIG. 4 is an exploded perspective view of the imaging
apparatus, showing an image sensor inclination adjusting mechanism
incorporated therein in an exploded state;
[0022] FIG. 5 is an enlarged sectional view taken along the line
V-V shown in FIG. 1; and
[0023] FIG. 6 is an enlarged sectional view taken along the VI-VI
shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] An embodiment of an imaging unit (imaging apparatus having
at least one bending optical element) 10 according to the present
invention will be discussed below with reference to FIGS. 1 through
6. In the following descriptions, forward and rearward directions,
leftward and rightward directions, and upward and downward
directions are determined with reference to the directions of the
double-headed arrows shown in FIGS. 1 through 6. The object side
corresponds to the front side. The thickness direction and the
widthwise direction of the imaging unit 10 correspond to the
forward/rearward direction and the upward/downward direction,
respectively. As shown by the outward appearance of the imaging
unit 10 in FIG. 1, the imaging unit 10 has a laterally elongated
shape which is slim in the forward/rearward direction (in the
thickness direction) and long in the leftward/rightward
direction.
[0025] As shown in FIGS. 2 and 3, the imaging unit 10 has an
imaging optical system which is provided with a first lens group
G1, a second lens group (rear lens group) G2, a third lens group
(rear lens group) G3 and a fourth lens group (rear lens group) G4.
The first lens group G1 is provided with a first prism (bending
optical element) L11, and the imaging unit 10 is provided with a
second prism (bending optical element) L12 on the right-hand side
of the fourth lens group G4. The imaging optical system of the
imaging unit 10 is configured as a bending optical system which
reflects (bends) a light bundle at substantially right angles at
each of the first prism L11 and the second prism L12. As shown in
FIG. 3, the first lens group G1 is configured of a first lens
element L1, the first prism L11 and a second lens element L2. The
first lens element L1 is positioned in front of (on the object side
of) an incident surface L11-a of the first prism L11, while the
second lens element L2 is positioned on the right-hand side of an
exit surface L11-b of the first prism L11. Each of the second lens
group G2, the third lens group G3 and the fourth lens group G4 is a
lens group which does not include a reflector element such as a
prism.
[0026] As shown in FIG. 3, a light bundle emanating from the
photographic object and incident on the first lens element L1 along
a first optical axis O1, which extends in the rearward direction
from the front of the imaging unit 10, enters the first prism L11
through the incident surface L11-a and is reflected by a reflecting
surface L11-c of the first prism L11 in a direction along a second
optical axis (pre-bending optical axis) O2 (extending in the
rightward direction) to exit from the exit surface L11-b of the
first prism L11. Subsequently, the light bundle exiting from the
exit surface L11-b passes through the second lens element L2 of the
first lens group G1 and the second through fourth lens groups G2,
G3 and G4 (the second through fourth lens groups G2, G3 and G4),
which lie on the second optical axis O2, and is incident on the
second prism L12 through an incident surface L12-a thereof.
Subsequently, the light bundle which is passed through the incident
surface L12-a is reflected by a reflection surface L12-c of the
second prism L12 in a direction along a third optical axis
(post-bending optical axis) O3 (extending in the forward direction)
and is incident on the imaging surface of an image sensor IS to
form an object image thereon. The first optical axis O1 and the
third optical axis O3 are substantially parallel to each other and
lie, together with the second optical axis O2, on a common plane
P1. The imaging unit 10 has a shape elongated in a direction along
the second optical axis O2, and the first lens element L1 is
positioned in the vicinity of an end (the left end) of the imaging
unit 10 with respect to the lengthwise direction thereof. The
second optical axis O2 constitutes an optical axis (pre-bending
optical axis) of the imaging optical system, and the third optical
axis O3 constitutes a post-bending optical axis of the imaging
optical system of the imaging optical system.
[0027] As shown in FIGS. 1 through 3, the imaging unit 10 is
provided with a body module 11 which holds the second lens group
G2, the third lens group G3, the fourth lens group G4, the second
prism L12 and the imaging sensor IS, and a first lens-group unit 12
which holds the first lens group G1. The body module 11 is provided
with a box-shaped housing 13 which is elongated in the
leftward/rightward direction and is small in thickness (slim) in
the forward/rearward direction. The first lens-group unit 12 is
fixed to one end (the left end) of the housing 13, with respect to
the lengthwise direction thereof, and the fourth lens group G4, the
second prism L12 and the imaging sensor IS are fixedly held at the
other end (the right end) of the housing 13, with respect to the
lengthwise direction thereof. However, the configuration of the
imaging unit 10 is not limited to the embodiment shown in FIGS. 1
through 3; for example, the body module 11 and the first lens-group
unit 12 can alternatively be formed as a single unitary member.
[0028] As shown in FIG. 2, the second lens group G2 and the third
lens group G3 are held by a second lens group frame 20 and a third
lens group frame 21, respectively, which are supported to be
movable along the second optical axis O2 by a pair of rods 22 and
23 provided in the housing 13. The imaging unit 10 is provided with
a first motor M1 and a second motor M2 which are supported by the
housing 13. When the first motor M1 is driven to rotate a screw
shaft M1a thereof which projects from the body of the first motor
M1, this rotation is transmitted to the second lens group frame 20
to move the second lens group frame 20 along the pair of rods 22
and 23. When the second motor M2 is driven to rotate a screw shaft
M2a thereof which projects from the body of the second motor M2,
this rotation is transmitted to the third lens group frame 21 to
move the third lens group frame 21 along the pair of rods 22 and
23. The imaging optical system of the imaging unit 10 is a zoom
lens system (variable-focal length lens system), and a zooming
operation (power-varying operation) is performed by moving the
second lens group G2 and the third lens group G3 along the second
optical axis O2. In addition, a focusing operation is performed by
moving the third lens group G3 along the second optical axis
O2.
[0029] The imaging unit 10 is provided with an anti-shake (image
shake correction/image-stabilizing/shake reduction) system that
reduces image shake on an image plane which is caused by vibrations
such as hand shake. This anti-shake system drives the first lens
element L1 of the first lens group G1 in a plane orthogonal to the
first optical axis O1. This anti-shake system itself is unrelated
to the gist of the present invention, and therefore, the
description thereof is omitted from the following descriptions.
[0030] FIGS. 4 through 6 show an embodiment of an inclination
adjusting mechanism for adjusting the inclination of the image
sensor IS that is positioned on the third optical axis O3, which is
bent by the reflecting surface L12-c of the second prism L12 of the
above described imaging apparatus. In the illustrated embodiment,
the image sensor IS is rectangular in a plan view, including a pair
of long sides IS-h and a pair of short sides IS-s, and the pair of
long sides IS-h face each other in the leftward/rightward direction
while the pair of short sides IS-s face each other in the
upward/downward direction as shown in FIG. 4. The image sensor IS
is fixed to a sensor board (image-sensor mounting board) 31. The
pair of long sides IS-h are orthogonal to the second optical axis
O2 in a plan view from the front (are each located at a right angle
relative to the second optical axis O2 without intersecting the
second optical axis O2). A light shielding member 32 is fixed to
the housing 13 to lie on the exit surface L12-b of the second prism
L12. The light shielding member 32 is provided at a center thereof
with a rectangular aperture 32a which allows a light bundle
emanating from a photographic object to pass therethrough. A
packing 33 and an inclination adjusting plate 34 are provided
between the sensor board 31 and the light shielding member 32. The
packing 33 is made of a resilient material which is formed into a
rectangular shape to correspond to the outside shape of the image
sensor IS.
[0031] The inclination adjusting plate 34 is provided with a
mounting plate portion 34a, a proximate plate portion 34b and a
curved plate portion 34c. The mounting plate portion 34a is for
mounting the image sensor IS. The proximate plate portion 34b is
parallel to the mounting plate portion 34a and is closer to the
housing 13 (closer to an imaginary plane P (see FIGS. 5 and 6)
which is orthogonal to a plane including both the second optical
axis O2 and the third optical axis O3 and includes the second
optical axis O2) than the mounting plate portion 34a. The curved
plate portion 34c connects the mounting plate portion 34a and the
proximate plate portion 34b. The inclination adjusting plate 34 and
the sensor board 31 are bonded to each other. The mounting plate
portion 34a is provided with a rectangular opening 34d, through
which the image sensor IS is exposed, and the inclination adjusting
plate 34 is further provided with an opening 34e which is formed
extending over the mounting plate portion 34a and the curved plate
portion 34c to expose electronic parts IS-p, which are contained on
the sensor board 31, through the opening 34e. A portion of the
inclination adjusting plate 34 on the left-hand side of the
rectangular opening 34d (on the side of the rectangular opening 34d
that is closest to the pre-bending optical axis (the second optical
axis O2) (and also closest to the first optical axis O1))
constitutes an inner end portion 34f, and another portion of the
inclination adjusting plate 34 on the right-hand side of the
rectangular opening 34d (on the side of the rectangular opening 34d
that is farthest from the pre-bending optical axis (the second
optical axis O2) (and also farthest from the first optical axis
O1)) constitutes an outer end portion 34g which includes the
proximate plate portion 34b and the curved plate portion 34c.
[0032] The housing 13 is provided with a support portion 13a for
the second prism L12 and is provided, on the outer side (right-hand
side) of the support portion 13a in the rightward direction, with
an inclination adjusting portion 13b. The housing 13 is provided on
the support portion 13a and the inclination adjusting portion 13b
with front projections 13c, 13d; 13e and 13f to correspond to the
outer shape of the inclination adjusting plate 34 (specifically the
outer shapes of the mounting plate portion 34a, the inner end
portion 34f and the outer end portion 34g) to define the planar
position of the inclination adjusting plate 34 on the housing
13.
[0033] The inclination adjusting plate 34 is provided, at the
center of the inner end portion 34f in the lengthwise direction
thereof, with a recessed portion 34h which is recessed one step
toward the housing 13 (toward the inclination adjusting portion
13b). In addition, the inclination adjusting plate 34 is further
provided, at the center of the recessed portion 34h on the sensor
board 31 side (on the opposite side of the inclination adjusting
plate 34 from the housing 13), with a fulcrum projection (swing
fulcrum) 34i which projects in a direction away from the second
prism L12 (away from the second optical axis O2 (the imaginary
plane P)). The housing 13 is provided with a contact portion 13g
which projects toward the support portion 13a and comes in contact
with the fulcrum projection 34i. The fulcrum projection 34i comes
in contact with the contact portion 13g from the second optical
axis O2 side (from the imaginary plane P side). The inclination
adjusting plate 34 can swing in directions to move the outer end
portion 34g (the proximate plate portion 34b) toward and away from
the housing 13 due to the contact engagement between the fulcrum
projection 34i and the contact portion 13g. An elongated hole 34j,
which is elongated in a direction parallel to the second optical
axis O2 and in which a guide pin 13h projecting from the housing 13
is slidably engaged, is formed in the proximate plate portion 34b
of the inclination adjusting plate 34 at a central position in the
proximate plate portion 34b with respect to the lengthwise
direction of the outer end portion 34g. The elongated hole 34j
allows the inclination adjusting plate 34 to move only in the
swinging direction about the point of contact between the fulcrum
projection 34i and the contact portion 13g.
[0034] On the other hand, a pair of compression coil springs
(biaser/inclination adjuster) 35, which are mutually identical in
specification and bias the proximate plate portion 34b in a
direction away from the housing 13 (the inclination adjusting
portion 13b), are installed on the mounting plate portion 34a (the
outer end portion 34g). The pair of compression coil springs 35 are
spaced from each other in the lengthwise direction of the outer end
portion 34g (i.e., the upward/downward direction), and are inserted
in between a pair of spring housing recesses 13i formed in the
housing 13 and a pair of spring-center protrusions 34m formed on
the mounting plate portion 34a, respectively.
[0035] A pair of adjustment screws (inclination adjuster) 36 for
lock-engaging the inclination adjusting plate 34 to the housing 13
against the biasing force of the pair of compression coil springs
35 are provided between the housing 13 and the inclination
adjusting plate 34, by extending through the housing 13 and the
inclination adjusting plate 34 to be screw-engaged with the
inclination adjusting plate 34 as shown in FIG. 6. The pair of
adjustment screws 36 are arranged to correspond to the pair of
compression coil springs 35 at positions closer to the outer side
(to a side (specifically the right-hand side) away from the
rectangular opening 34d) than the pair of compression coil springs
35. A pair of screw-insertion through-holes 13j are formed in the
housing 13, and a pair of female screw holes 34k, in which the pair
of adjustment screws 36 are screw-engaged, are formed in the
proximate plate portion 34b of the inclination adjusting plate 34.
Each adjustment screw 36 is provided with a large-diameter head
36b, and the large-diameter heads 36b of the pair of adjustment
screws 36 are engaged with the inclination adjusting portion 13b.
The ends 36a (upper ends with respect to FIG. 6) of the threaded
portions of the pair of adjustment screws 36 project toward the
inclination adjusting plate 34 side from the inclination adjusting
portion 13b side. In a state where the ends 36a of the threaded
portions of the pair of adjustment screws 36 are screw-engaged with
the pair of female screw holes 34k, respectively, the ends 36a of
the threaded portions of the pair of adjustment screws 36 are
positioned closer to the housing 13 (the imaginary plane P) than an
extension plane extended from the sensor board 31 in the
forward/rearward direction, i.e., at positions below this extension
plane with respect to FIG. 6.
[0036] In the above described inclination adjusting apparatus for
adjusting the inclination of the image sensor IS, the image sensor
IS can be made to fall into a temporarily engaged state by
positioning the inclination adjusting plate 34 to which (to the
mounting plate portion 34a of which) the image sensor IS is mounted
inside the front projections 13c, 13d, 13e and 13f, fitting the
elongated hole 34j onto the guide pin 13h, inserting the pair of
adjustment screws 36 into the pair of screw-insertion through-holes
13j from behind the inclination adjusting portion 13b, and screwing
the ends 36a of the threaded portions of the pair of adjustment
screws 36 into the pair of female screw holes 34k. In this
temporarily engaged state, the inclination adjusting plate 34 can
be made to tilt (swing) about the point of contact between the
contact portion 13g and the fulcrum projection 34i, and the
inclination of the image sensor IS relative to the third optical
axis O3 can be adjusted by individually adjusting the amount of
screwing of each adjustment screw 36 to the associated female screw
holes 34k. The pair of compression coil springs 35 and the pair of
adjustment screws 36 constitute an inclination adjuster.
[0037] The present embodiment of the inclination adjusting
apparatus for the image sensor IS does not cause an increase in
either width or thickness of the housing 13. Moreover, the ends 36a
of the threaded portions of the pair of adjustment screws 36 do not
project outside (beyond) the external periphery of the housing 13
in the thickness direction thereof because the proximate plate
portion 34b of the inclination adjusting plate 34 is recessed one
step rearward (so as to approach the imaginary plane P) in the
thickness direction of the housing 13 from the position of the
mounting plate portion 34a and because the pair of female screw
holes 34k are formed in the proximate plate portion 34b thus
recessed rearward.
[0038] Although the pair of long sides IS-h of the image sensor IS
are orthogonal to the second optical axis O2 in a plan view from
the front in the above described embodiment of the imaging
apparatus, it is possible for the image sensor IS to be arranged so
that the pair of short sides IS-s are orthogonal to the second
optical axis O2 in a plan view from the front. In addition, the
present invention can also be applied to an imaging apparatus using
a square-shaped image sensor which corresponds to the image sensor
IS (note that a rectangle includes a square).
[0039] Although the pair of compression coil springs 35 and the
pair of adjustment screws 36 are installed at different positions
in the above described embodiment of the imaging apparatus, it is
possible for the pair of compression coil springs 35 to be fitted
concentrically on the pair of adjustment screws 36,
respectively.
[0040] Although the imaging optical system of the above-described
imaging apparatus has the first prism L11, the present invention
can also be applied to a imaging apparatus which does not include a
prism that corresponds to the first prism L11. Additionally,
although the second lens group G2, the third lens group G3 and the
fourth lens group G4 are provided on the second optical axis O2,
the present invention can also be applied to a type of imaging
optical system in which less than or more than three lens groups
are provided on an optical axis of the imaging optical system which
corresponds to the second optical axis O2.
[0041] Additionally, in the first lens group G1, it is possible to
change the number of lens elements arranged in front of the
incident surface L11-a of the first prism L11 on the first optical
axis O1 and the number of lens elements arranged on the right-hand
side (the object image side) of the exit surface L11-b of the first
prism L11 on the second optical axis O2.
[0042] Additionally, although the imaging optical system of the
above illustrated embodiment of the imaging unit 10 is a zoom lens
(variable power optical system) which performs a zooming operation
(power varying operation) by moving the second lens group G2 and
the third lens group G3 along the second optical axis O2, the
present invention is also applicable to an imaging apparatus which
incorporates an imaging optical system having no power varying
capability. For instance, it is possible to modify the imaging unit
10 such that the second lens group G2 and the third lens group G3
do not move for a zooming operation and that the second lens group
G2 or the third lens group G3 moves solely for a focusing
operation.
[0043] Although the incident surface L11-a of the first prism L11
in the above illustrated embodiment of the imaging unit 10 is in
the shape of a laterally elongated rectangle, the present invention
can also be applied to a type of imaging apparatus (imaging optical
system) having a first prism (which corresponds to the first prism
L11), the incident surface thereof having a different shape such as
a square or a trapezoid.
[0044] Obvious changes may be made in the specific embodiment of
the present invention described herein, such modifications being
within the spirit and scope of the invention claimed. It is
indicated that all matter contained herein is illustrative and does
not limit the scope of the present invention.
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